Innovative formwork will speed construction of below-grade construction at the $110 million Capitol Hill Station.

February 25, 2013 |

BD+C Staff

To speed construction of the $110 million Capitol Hill Station light-rail station in Seattle, general contractor Turner Construction will use an unusual temporary framing method for the project's underground spaces.

Like building a ship in a bottle, the "collapsible" steel truss system will be lowered into the shaft and expanded to form the framework for the station's concrete walls and floors, according to CHS Capitol Hill Seattle Blog.

Using the steel truss system, Turner will complete 40 feet at a time. Once the concrete is dry, the framework will be collapsed and used to create the next section. The frame system also incorporates PVC piping that will circulate cool water to assist in concrete curing time.

The report, “Spending Through the Roof,” says that apartment building owners pay an average of $3,400 a year to replace heat lost through the roof. In taller buildings, the cost can be more than $20,000 a year. Illustration: Urban Green Council